Lost wax casting, a 4000 year old process, is still used today in most types of casting operations that utilize sacrificial patterns. The jewelry casting industry is one of the more prevalent practitioners of the process. It has advanced over the years from using hand carved patterns to current production processes which use rubber molds for creating duplicate sacrificial wax patterns. In contemporary processes, molten wax is injected under pressure into the mold cavity and, because of the frailty of the wax, removed by hand when the wax has hardened. This is a labor intensive, costly process which negates the fact that wax is inexpensive. Wax is cheap and reliable but has limitations. Some plastics have been used for sacrificial patterns but because of the nature of injectable plastics, those patterns have been limited to simple parts. The rigid molds required by the plastic materials do not allow for the complex undercuts that are present in the majority of jewelry patterns. In other words, undercuts create a mechanical lock that does not allow the part to be released from the mold.